الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Vascular anomalies (VAs) represent a spectrum of disorders from a simple “birthmark” to life- threatening entities. Incorrect nomenclature and misdiagnoses are commonly experienced by patients with these anomalies. Accurate diagnosis is crucial for appropriate evaluation and management, often requiring multidisciplinary specialists. Classification schemes provide a consistent terminology and serve as a guide for pathologists, radiologists, clinicians, and researchers.
Over the past 2 decades, various subspecialists have adopted a new classification system proposed by the International Society for the Study of Vascular Anomalies (ISSVA), which divides vascular anomalies into 2 main categories: tumors and malformations. This system provides a systematic approach to VAs that correlates histopathology with clinical course and therapy.
Vascular tumors are endothelial neoplasms; they include the benign IHs and CHs as well as the borderline malignant rare KHEs, among others. IHs are by far the most common lesions; clinically they feature an early phase of rapid proliferation followed by a later stage of involution. Vascular malformations are developmental anomalies that are already present at birth but may go initially unnoticed. Unlike hemangiomas, they grow proportionately with the child and do not regress. They are subdivided into low- versus high flow malformations. Low flow malformations include various combinations of venous, capillary, and lymphatic elements, whereas high malformations have arterial component and include AVMs and AVFs.
The diagnosis of a soft-tissue VA is primarily based on the clinical examination. Imaging is usually reserved for therapeutic planning, and lesions with unclear diagnosis or deep-tissue involvement. Currently, US and MRI are the two noninvasive imaging techniques of choice. Gray-scale US with color Doppler assessment is a good imaging modality for the initial assessment and characterization of such lesions because it enables differentiation of high- from low-flow lesions. Its main limitations are insufficient FOV and tissue penetration as well as operator dependency. Many VAs grow in an infiltrative fashion and can involve multiple tissue planes. MRI helps overcome all these limitations and provides superior tissue characterization. It is unsurpassed in showing lesion extent and involvement of different tissue planes and joints. The anatomic extent of the lesion is best seen on fluid-sensitive sequences, such as fat-suppressed fast spin-echo (FSE) T2-weighted or STIR imaging.
Differentiation between high flow and low flow lesions is crucial as treatment plan will change.
In our study gray-scale US coupled with color Doppler flow imaging and spectral analysis was compared to DCE MRA in diagnosis of vascular anomlaies in pediatric age grop .And it had been found that US is of relatively high sensitivity and specificity in patients with soft tissue lesions of presumed vascular origin compared to DCE MRA owing to its ability to distinguish hemangioma, a tumor of solid tissue, from vascular malformations composed of abnormal vessels or cysts, and lesions containing arteries from those in which arterial flow is absent. These distinctions are of great value in directing subsequent investigation and management, since prognosis and appropriate treatment vary substantially for each type of anomaly.
Our results showed that the US had a sensitivity of 100%, specificity of 86.4% and accuracy of 84.0% in detection of hemangioma compared to MRI. The US had a sensitivity of 53.8 %, specificity of 91.7% and accuracy of 88% in detection of venous malformation compared to MRI. US had a sensitivity of 33.3 %, specificity of 95.5 % and accuracy of 88% in detection of Klippel trenaunay syndrome compared to MRI. While the US had a sensitivity of 33.3%, specificity of 90.9 % and accuracy of 84% in detection of lymphatic malformation compared to MRI. In the case of mixed low flow malformation US had sensitivity of 0%, specificity of 91.3% and accuracy of 84%.
The previously stated results denote that US has high sensitivity & specificity in diagnosis of vascular anomalies especially in hemangioma; thus when imaging is needed in diagnosis of vascular malformations US should be considered positively.